The present invention relates to arch or bridge assemblies used in cruisers and other watercraft for supporting radar antennas and other equipment, and more particularly to mechanisms for controlling movement of such assemblies between a generally upright position for use, and a lowered position for stowage, on-land transit or for allowing the watercraft to pass under bridges and other obstructions having low clearance.
For years, cabin cruisers and other watercraft have employed arch-shaped structures for supporting radar antennas, radio antennas and other electronic equipment above the normal deck level. A typical arch assembly includes an opposed pair of generally upright legs secured to the gunwales or elsewhere on opposite sides of the hull, and a transverse bridge member or transom attached to the tops of the legs and spanning the distance between them. Typically, the equipment is mounted to the bridge member.
While effective in supporting antennas and other equipment, the arch assembly increases the need for overhead clearance, whether the cruiser is in use or mounted on a trailer for towing. Stowage can be more difficult, and more expensive in facilities that charge by the cubic foot. While arch assemblies can be mounted in a manner that allows their detachment for the hull when the cruiser encounters a bridge or other overhead obstruction, detachment and reattachment are difficult in view of the weight and bulk of the arch assembly. An arch-shaped structure can be mounted pivotally relative to the gunwales, as shown in U.S. Pat. No. 6,986,321 (Metcalfe) in connection with a wake tower for towing a wake boarder or water skier. This still calls for manual handling, which can be difficult in view of the larger size and weight of arch assemblies as compared to the wake tower shown in Metcalfe.
U.S. Pat. No. 4,694,773 (Sparkes et al.) discloses a power system for raising and lowering an arch assembly. Each lower end of the arch is mounted to pivot relative to the boat through a top cover component and a lower base mounting component. A hydraulic motor within the base component is operable to extend a rod, pivoting a bracket to raise the arch. The arch can be lowered by allowing it to descend by gravity. The rod retracts, dampened by the hydraulic motor cylinder.
While this approach is effective from the standpoint of powering the arch assembly, it requires a bulky, unsightly housing at the base of each leg, along with an exposed pivotal coupling between separate components of the mechanism. In a competitive marketing environment where aesthetic appeal carries considerable weight, the arch assembly typically is treated as a feature of the cruiser design, either to blend in with the rest of the vessel or create its own impact on the overall appearance. Thus, the functional utility of any conventional arch assembly control mechanism is countered by the unwanted alteration in the appearance of the arch, the watercraft hull near the arch, or both. Accordingly, the present invention has several aspects directed to one or more of the following objects:
to provide a system for raising and lowering an arch assembly of a watercraft through linkage and motive components that are recessed into the arch assembly or hull, and are hidden from view when the arch assembly is in the generally upright working position;
to provide a linkage between a watercraft hull and an arch assembly adapted to guide the arch assembly through a controlled sequence and combination of linear travel and rotation as the assembly is moved from a generally upright working position to a clearance position;
to provide a linkage coupling an arch assembly for controlled movement relative to a watercraft hull, configured to maintain the arch assembly in a generally upright orientation for linear travel when the arch assembly is within a predetermined distance of the hull, while permitting the arch assembly to rotate relative to the hull when separated from the hull by more than the predetermined distance; and
to provide a mechanism for controlling movement of an arch assembly between working and clearance positions relative to a watercraft hull through a linear actuator operable to both linearly translate and pivot the arch assembly.